In Orexo AB v. Actavis Elizabeth LLC [2017-1333] (September 10, 2018), the Federal Circuit reversed the district court’s determination that the challenged claims of U.S. Patent No. 8,940,330 were invalid for obviousness.

The invention related to pills for treating opioid addiction that were less susceptible to misuse, where the active ingredient, buprenorphine, was adhered to carrier particles of citric acid. The district court relied upon a patent disclosing the use of citric acid to reduce the pH of an orally dissolvable film.

The Federal Circuit, however, found that the claimed structure was achieved solely upon the hindsight knowledge of the structure and benefits described in the ’330 Patent.

Orexo argued that citric acid is nowhere used, listed or suggested as a carrier particle in the prior art, and at oral argument Actavis conceded that no reference teaches using citric acid as a carrier particle or that citric acid should be used as a carrier particle.

The district court’s finding that a person of ordinary skill in the art would not have excluded citric acid was not the same as a teaching or suggestion to use citric acid. The Federal Circuit observed that the mere fact that the prior art could be so modified would not have made the modification obvious unless the prior art suggested the desirability of the modification. The Federal Circuit said that the record does not contain clear and convincing evidence of a teaching or suggestion to use citric acid particles as a carrier for this opioid product in substitution therapy, or that the actual beneficial results would be obtained.

In response to the district court’s observation that “there is nothing in the prior art which would have discouraged a person of ordinary skill from following the path set out in the various references,” the Federal Circuit said that “no reference or combination of references proposes the path of the ’330 Patent.”

The district court erred in discounting objective indicia of nonobviousness, and concluded that obviousness had not been established by clear and convincing evidence.